SYDNEY -- The Marvel universe moves into the cosmic realm with the 3D Thor, a burly slab of bombastic superhero entertainment that skitters just this side of kitschy to provide an introduction befitting the mighty god of thunder. It’s a noisy, universe-rattling spectacle full of sound and fury with a suitably epic design, solid digital effects and a healthy respect for the comic-book lore that turned a mythological Norse god into a founding member of the superhero team known as The Avengers. Following its world premiere in Sydney April 17, Thor opens in various territories before its North American bow May 6.

The arrogant warrior Thor’s great conversion, central to the plot, is unrealistically lightning-quick and the movie’s dramatic arc falters amid the constant shifts between earthly and celestial realms. But execs at Marvel Studios, gambling heavily on the success of Thor and the upcoming Captain America: The First Avenger to set up next summer’s ensemble behemoth The Avengers, can rest easy: You’ve built it and they will come. They may even bring a date.

The ultimate accessibility of Thor’s fantastical world is due in no small measure to the good-humored direction of Kenneth Branagh, a man with a highbrow history who knows his way around an epic tale, and a star-making turn from Chris Hemsworth.

As the hammer-wielding protagonist who learns humility among the humans, the little-known Aussie soap star (last seen briefly as Captain Kirk’s father in J.J. Abrams’ Star Trek reboot) shoulders the burden of selling this $150 million entrant into the ever-expanding Marvel franchise.

Branagh may convey a lofty intellect to the Shakespearean interplay of feuding fathers and sons, and co-stars Anthony Hopkins and Natalie Portman the actorly gravitas. But the 6-foot-3 Hemsworth adds the winning ingredients, bringing a lusty Viking charm to his rumbling Olde English line readings, a towering physicality and biceps that look forged in a furnace. Verily, he is ripped.

Thor crashes into being in a desolate stretch of New Mexico desert, his face planted inelegantly against the windscreen of an RV driven by Natalie Portman’s storm-chasing scientist Jane Foster.

As Jane, her mentor Dr. Erik Selvig (Stellan Skarsgard) and sidekick Darcy (Kat Dennings, from Nick and Nora’s Infinite Playlist, along purelyfor comic relief) puzzle over his provenance, we whip back in time and space to the floating kingdom of Asgard, where Thor’s father Odin (Hopkins), the ruler of all nine realms, fills in decades of back story in voiceover.

It’s heavy stuff, made all the more portentous by Patrick Doyle’s somewhat overwhelming score, and thankfully there’s someone of Hopkins’ caliber to deliver it.

Thor is about to inherit the throne from the ailing and aged Odin when an unexpected incursion by the Asgardians’ longstanding foes, the Frost Giants of Jotunheim, disrupts the coronation.

The mighty god of thunder, foe to all demons, suddenly does a very good impression of a toddler throwing a tantrum in a supermarket aisle. His hot-tempered recklessness has even more dire consequences though: The peace and stability of the universe is threatened.

An enraged Odin strips Thor of his powers and banishes him to Earth, leaving Thor’s half-brother Loki next in line to the throne and Thor with the task of proving himself worthy of again wielding his magical hammer Mjolnir.

The scenes between the three immortals high in the heavens have an electrifying intensity – Tom Hiddleston as the jealous and snaky Loki handles the intimate scenes with particular aplomb – and the earth-bound scenes can’t help but seem flat by comparison.

Back in the desert, we get some solidly amusing fish-out-of-water antics as the mighty Thor struggles to adapt to his mortality and a world of Facebook and iPods, but scriptwriters Ashley Edward Miller, Zack Stentz and Don Payne working from an effective origin story by J. Michael Straczynski and Mark Protosevich, have their eye on a bigger prize.

It’s the love of a good woman that powers Thor’s life lesson in humility and humanity and Portman’s astrophysicist makes short work of converting Thor; too short, some will say, but there’s much story to cram in here and we haven’t even gotten to that oddly out-of-place glimpse of Jeremy Renneras The Avenger’sHawkeye.

The action pinballs between Asgard, the desolate ice planet of Jotunheim, and Earth, where a S.H.I.E.L.D. agent from the Iron Manfilms (Clark Gregg) is making it difficult for Thor to retrieve his magic hammer and save the humans and the kingdom of Asgard from the forces that would destroy them.

Bo Welch has created some stunning designs, with Heimdall’s Observatory, the celestial portal that connects the various realms, a particular triumph. Full-throttle fight scenes and the stunt work overall feel organic, although Branagh’s over-reliance on slanted angles and an unusual slow-mo sequence are merely distracting.

Following its world premiere in Sydney April 17, Thor opens in various territories before its US bow on May 6.